Your BODY thinks for you....

Mind over matter? How your body does your thinking

New Scientist 24 March 2010 by Anil Ananthaswamy

Editorial: It's not mind or body - it's both

"I THINK therefore I am," said Descartes. Perhaps he
should have added: "I act, therefore I think."

Our ability to think has long been considered central to
what makes us human. Now research suggests that our bodies
and their relationship with the environment govern even
our most abstract thoughts. This includes thinking up
random numbers or deciding whether to recount positive or
negative experiences.

"Advocates of traditional accounts of cognition would be
surprised," says Tobias Loetscher at the University of
Melbourne in Parkville, Australia. "They generally
consider human reasoning to involve abstract cognitive
processes devoid of any connection to body or space."

Until recently, the assumption has been that our bodies
contribute only to our most basic interactions with the
environment, namely sensory and motor processes. The new
results suggest that our bodies are also exploited to
produce abstract thought, and that even seemingly
inconsequential activities have the power to influence our
thinking.

Clues that our bodies may play a role in thought can be
found in the metaphors we use to describe situations, such
as "I was given the cold shoulder" or "she has an
excellent grasp of relativity".

Thirty years ago, such observations led the linguist and
philosopher George Lakoff at the University of California,
Berkeley, together with philosopher Mark Johnson at the
University of Oregon in Eugene, to propose "metaphor
theory", the notion that we think of abstract concepts in
terms of how our bodies function. Now evidence for the
theory has started to trickle in. In 2008, for example,
researchers found that people made to feel socially
excluded reported feeling physically colder.

Now, Loetscher and his colleagues have linked our ability
to think of random numbers - an example of abstract
thought - to bodily movements.

His team asked 12 right-handed men to generate a string of
40 numbers, each between 1 and 30, in as random a sequence
as possible. The researchers recorded the vertical and
horizontal movements of the men's eyes as they spoke the
numbers out loud to the beat of a metronome.

The team found that the eye movements could be used to
predict the size of the next number before it was spoken.
If a volunteer looked left and downwards, he would
typically chose a number that was smaller than the
previous number, and if he looked up and to the right, he
chose a number that was larger (Current Biology, DOI:
10.1016/j.cub.2010.01.015). What's more, the extent to
which he looked in a particular direction correlated with
the extent to which the number was larger or smaller than
the last. The result strongly suggests that abstract
thought is tied to the physical movements of our bodies,
says Loetscher.

But why would two seemingly unconnected things -
apparently inconsequential eye movements and random
numbers - be connected? Lakoff, who calls Loetscher's
experiment a "particularly beautiful example" of embodied
cognition, says it is to do with how our ability to think
develops during childhood.

Lakoff reckons that the volunteers are making use of two
sets of metaphors for imagining numbers: that up is more
and down is less, and that right is more and left is less.
Such metaphors would have been learned and hard-wired into
the brain at a young age. A child watching a glass of
water being filled up, or building blocks piled up, will
learn that increasing height means greater quantity, for
example. Separate brain regions that process quantity and
height could then have been linked up in the growing
brain, he says, leading to a hard-wired understanding of
the metaphor that up is more. Similarly, right-handed
people may learn to link right with more because that hand
is dominant for them.

What's not clear from Loetscher's experiment, however, is
if eye movements are driving the number selection, or if
the number selection triggers particular eye movements.

To probe whether movements can drive thought, Daniel
Casasanto of the Max Planck Institute for
Psycholinguistics in Nijmegen, the Netherlands, turned to
the metaphors that we use to speak of our moods. "We can
hardly help mapping them onto a vertical, spatial schema,
with the good end 'up' and the bad end 'down'," says
Casasanto. "We talk of being high on life, or our mood
taking an upswing, or feeling down in the dumps."

We map our moods onto a vertical, spatial schema, with the
good end 'up' and the bad end 'down'

His team asked 24 students to move marbles from a box on a
higher shelf to one on a lower shelf, or vice-versa, while
talking about events that had positive or negative
emotional significance - such as a time when they were
proud or ashamed of themselves.

As it turns out, the students were significantly faster at
retrieving and retelling stories that chimed with the
metaphor implied by their actions. So if they were moving
marbles upwards, they were faster at retelling stories
with positive emotional content than those linked to
negative emotions, and vice versa (Cognition, DOI:
10.1016/j.cognition.2009.11.002).

The results also led to a deeper question: does physical
movement have the power to change not just the speed at
which people talk, but also what they choose to talk - or
even think - about? Casasanto's next experiment found that
it does.

As the students were moving the marbles either up or down,
they were asked neutral questions, such as "tell me what
happened yesterday". In this task, the subjects were more
likely to talk of positive happenings when they were
moving marbles upwards, and narrate negative stories when
moving marbles downwards. "Isn't that somewhat scary?"
Casasanto asks.

They would talk positively when moving marbles upwards,
but negatively when moving them down

If bodily motions really are driving our thoughts,
Casasanto reasoned that people who use their bodies
differently should have different thoughts. To test this,
he turned to left-handed people. He asked 286 students, 40
of whom were left-handers, to make judgements about
cartoon characters called Fribbles. A page contained 12
pairs of Fribbles and members of each pair looked similar
but had distinguishing features. In each pair one member
was located to the right and the other to the left of a
question.

The questions asked students to circle one of each pair
based on their judgement of its personal characteristics,
such as honesty, happiness, intelligence and
attractiveness. They were either worded positively (which
Fribble is the most attractive) or negatively (which
Fribble looks less attractive).

The researchers found that 210 students showed a leftward
or rightward preference and, of these, 65 per cent of the
left-handers attributed positive attributes more often to
the Fribbles on the left, while 54 per cent of the
right-handers saw positive attributes in Fribbles to the
right (Journal of Experimental Psychology, DOI:
10.1037/a0015854). "Righties think right is good, and
lefties think left is good," Casasanto concludes.

This bias towards ascribing positive virtues to our
dominant side may also be reflected in sayings such as "my
right-hand man", or "two left feet", which may have arisen
because most people are right-handed.

If the inherent characteristics of our bodies are
responsible for our abstract thoughts - what does that
mean for bodies that are drastically different to our own?

Lakoff says that if intelligent aliens exist, they may
have very different bodies and therefore have developed
very different abstract thought - even perhaps a different
mathematical system. "People assume that mathematics is
objective and that everybody will have the same math,"
says Lakoff. "But there is no reason to believe that."